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Techniques

Over the years ACM have built up a collection of test techniques applicable to standard instruments such as Gill AC, Gill 8 or Field Machine:

  • AC Impedance (EIS) - a series of sine waves from start to finish frequencies. Potential and galvanic response for each wave is stored, from which Z Real, Z Imaginary, Bode Impedance and Bode Theta are calculated.  Download apn-AC Impedance-v1.0.pdf for more information.
  • Current & Voltage Noise - continuous measurement of potential and galvanic readings. Maximum read rate is limited by the mains frequency, 50 per second for 50Hz and 60 per second for 60Hz. Download apn-Current&VoltageNoise-v1.0.pdf for more information.  See also 0.1Hz Coulometry
  • 0.1Hz Coulometry - a method of monitoring and quantifying pitting, crevice and other localised corrosion on passive metals such as stainless steel.
  • Cyclic Sweep - sweeps between two potentials over a number of cycles, or half cycles.  Can be used for Tafel Analysis and Cyclic Voltammetry. Download apn-CyclicVoltammetry-v1.0.pdf for more information.
  • Harmonic Analysis - extracts first, second and third harmonics and calculates corrosion rate.
  • Potential Measurement & Galvanic Measurement.
  • Potentiostatic - hold offset potential and measure current response. Download apn-Potentiostatic-v1.0.pdf for more information.
  • Galvanostatic - maintain offset current and measure potential response.
  • Galvanic Sweep - potential is measured whilst current is swept.
  • Linear Polarisation Resistance (LPR) - both sweep & step (more resilient) tests available, results plotted as LPR result vs time or corrosion rate Download apn-LPR-v1.0.pdf for more information.
  • Inhibitor testing - See Bubble Test below.
  • Bubble Test - Primarily used for testing of oil field inhibitors. Also referred to as Kettle Test and Inhibitor Screening. They are all tests that use the LPR technique with respect to time to calculate the efficiency of oil field inhibitors. Download apn-Inhibitors-v1.0.pdf for more information.
  • Voltage Input - measure external potentials, thermocouple inputs can be specified.
  • IR Compensation - typically used for measurement of concrete samples or other high impedance samples. Download apn-IRCompensation-v1.0.pdf for more information.
  • Weld Testing - many of the standard techniques can be supplied for weld testers, 5 simultaneous weld measurements.Download apn-Welds-v1.0.pdf for more information.
  • Bubble Test using L.C.M.TM - Localised Corrosion Monitoring developed by ACM Instruments and Baker Petrolite.

More exotic, or custom created techniques:

  • Custom Sweep - finer control of sweeps, pauses and offsets.
  • Multiphase Flow - ACM's own designed technique (Patent No.: GB2365977) for use in multiphase environments. Download apn-LPRNoiseInMPE-v1.0.pdf for more information.
  • Temperature Measurement - Platinum Resistance Thermometers (PRT) give the highest accuracy measurement.
  • ER - Electrical resistance, precision measurement of ER probes. Download apn-ER-v1.0.pdf for more information.
  • GPS Positioning - Add-on for field machine to log position, later plotted on a map.
  • Critical Pitting Temperature - Download apn-CriticalPittingTemperature-v1.0.pdf for more information.
  • Concrete testing - A Guard Ring is used to monitor a specific area of rebar beneath a layer of concrete. Download apn-GuardRing-v1.0.pdf and apn-Concrete-v1.0.pdf for more information.
  • Paints and Coatings - Femto Amp (was called Paint Buffer) is a very sensitive instrument, able to measure currents down at the level of femtoamps and offering incredibly high input impedance. An option for Gill AC and Gill 6 / 8 / 12. Download apn-NonMetallicCoatings-v1.0.pdf for more information.
  • Current Step Polariser - Define precise current steps whilst potential is measured.
  • Heater & Stirrer Control - From within sequencer heaters and stirrers can be controlled.

See Application Notes for additional information. Also includes details on how to limit noise pick up in your system.

The Videos section includes demonstrations of how to set up techniques using our software.

There are endless options with ACM, we are masters of bespoke system design, always happy to discuss individual requirements.   Please contact us for more information.